body {
    position: absolute;
    width: 100%;
    height: 100%;
    margin: 0px;

    background-image: url("../images/indexBackground.jpg");
    background-size: cover;

    display: flex;
    justify-content: center;
    align-items: center;

    font-family: Helvetica, 'Hiragino Sans GB', 'Microsoft Yahei', '微软雅黑', Arial, sans-serif;
    font-size: 3ex;
    color: #333333;
}

#mainContainer {
    right: 400px;
    padding: 10px;
    position: relative;
    width: 400px;
    height: 600px;
    background:rgba(255,255,255,0.6);
    border-radius: 8px;
    box-shadow: 3px 3px 10px rgba(0,0,0,0.1);
    backdrop-filter: blur(25px);
    -webkit-backdrop-filter: blur(25px);
